Cranberry syrup vs trimethoprim in the prophylaxis of recurrent urinary tract infections among children: a controlled trial

Objectives: The present study forms part of the ISRCTN16968287 clinical assay. The objective of this study was to determine the effectiveness of cranberry syrup in the prophylaxis of recurrent urinary tract infection (UTI). Design: Phase III randomized clinical trial. Setting: The study was conducted at the San Cecilio Clinical Hospital (Granada, Spain). Participants: A total of 192 patients were recruited. The subjects were aged between 1 month and 13 years. Criteria for inclusion were a background of recurrent UTI (more than two episodes of infection in the last 6 months), associated or otherwise with vesicoureteral reflux of any degree, or renal pelvic dilatation associated with UTI. Criteria for exclusion from recruitment to the study included the co-existence of UTI with other infectious diseases or with metabolic diseases, chronic renal insufficiency, and the presence of allergy or intolerance to any of the components of cranberry syrup or trimethoprim. Primary outcome measures: The primary objective was to determine the risk of UTI associated with each intervention. Results: Of the 198 patients initially eligible, 192 were finally included in the study to receive either cranberry syrup or trimethoprim. UTI was observed in 47 patients, 17 of whom were males and 30 females. We recruited 95 patients diagnosed with recurrent UTI on entry; during follow-up, 26 patients had a UTI (27.4%, 95% CI: 18.4%-36.3%). Six patients (6.3%) were male and 20 (21.1%) were female. Eighteen patients (18.9% of the total, 95% CI: 11%-26.3%) receiving trimethoprim had a UTI and eight patients (8.4% of the total, 95% CI: 2.8%-13.9%) were given cranberry. Sixty-six percent of the episodes of UTI recurrence were caused by Escherichia coli, with no significant differences being found between the two treatment branches. No differences were observed between the two treatment branches in the rate of resistance to antibiotics. Conclusion: Our study confirms that cranberry syrup is a safe treatment for the pediatric population. Cranberry prophylaxis has noninferiority with respect to trimethoprim in recurrent UTI. (European Clinical Trials Registry EuDract 2007-004397-62) (ISRCTN16968287).